Merge bitcoin#29252: kernel: Remove key module from kernel library

96378fe Refactor: Remove ECC_Start and ECC_Stop from key header (TheCharlatan)
41eba5b kernel: Remove key module from kernel library (TheCharlatan)
a08d2b3 tools: Use ECC_Context helper in bitcoin-tx and bitcoin-wallet tools (Ryan Ofsky)
28905c1 test: Use ECC_Context helper in bench and fuzz tests (Ryan Ofsky)
538fedd common: Add ECC_Context RAII wrapper for ECC_Start/ECC_Stop (Ryan Ofsky)

Pull request description:

  The key module's functionality is not used by the kernel library, but currently kernel users are still required to initialize the key module's `secp256k1_context_sign` global as part of the `kernel::Context` through `ECC_Start`. So move the `ECC_Start` call to the `NodeContext` ctor instead to completely remove the key module from the kernel library.

  The gui tests currently keep multiple `NodeContext` objects in memory, so call `ECC_Stop` manually to avoid triggering an assertion on `ECC_Start`.

  ---

  This PR is part of the [libbitcoinkernel project](bitcoin#27587). It removes a module from the kernel library.

ACKs for top commit:
  achow101:
    ACK 96378fe
  ryanofsky:
    Code review ACK 96378fe. Just suggested comment changes since last review.
  theuni:
    utACK 96378fe

Tree-SHA512: 40be427e8e2c920c0e3ce64a9bdd90551be27a89af11440bfb6ab0dd3a1d1ccb7cf1f82383cd782818cd1bb44d5ae5d2161cf4d78d3127ce4987342007090bab

Author: achow101

src/Makefile.am

@@ -945,7 +945,6 @@ libbitcoinkernel_la_SOURCES = \
   kernel/disconnected_transactions.cpp \
   kernel/mempool_persist.cpp \
   kernel/mempool_removal_reason.cpp \
-  key.cpp \
   logging.cpp \
   node/blockstorage.cpp \
   node/chainstate.cpp \

src/bench/bip324_ecdh.cpp

@@ -14,7 +14,7 @@
 
 static void BIP324_ECDH(benchmark::Bench& bench)
 {
-    ECC_Start();
+    ECC_Context ecc_context{};
     FastRandomContext rng;
 
     std::array<std::byte, 32> key_data;
@@ -44,8 +44,6 @@ static void BIP324_ECDH(benchmark::Bench& bench)
         // - Copy 16 bytes from the resulting shared secret into the middle of their ellswift key.
         std::copy(ret.begin() + 16, ret.end(), their_ellswift_data.begin() + 24);
     });
-
-    ECC_Stop();
 }
 
 BENCHMARK(BIP324_ECDH, benchmark::PriorityLevel::HIGH);

src/bench/ccoins_caching.cpp

@@ -18,7 +18,7 @@
 // (https://github.com/bitcoin/bitcoin/issues/7883#issuecomment-224807484)
 static void CCoinsCaching(benchmark::Bench& bench)
 {
-    ECC_Start();
+    ECC_Context ecc_context{};
 
     FillableSigningProvider keystore;
     CCoinsView coinsDummy;
@@ -47,7 +47,6 @@ static void CCoinsCaching(benchmark::Bench& bench)
         bool success{AreInputsStandard(tx_1, coins)};
         assert(success);
     });
-    ECC_Stop();
 }
 
 BENCHMARK(CCoinsCaching, benchmark::PriorityLevel::HIGH);

src/bench/checkqueue.cpp

@@ -25,7 +25,7 @@ static void CCheckQueueSpeedPrevectorJob(benchmark::Bench& bench)
     // We shouldn't ever be running with the checkqueue on a single core machine.
     if (GetNumCores() <= 1) return;
 
-    ECC_Start();
+    ECC_Context ecc_context{};
 
     struct PrevectorJob {
         prevector<PREVECTOR_SIZE, uint8_t> p;
@@ -62,6 +62,5 @@ static void CCheckQueueSpeedPrevectorJob(benchmark::Bench& bench)
         // it is done explicitly here for clarity
         control.Wait();
     });
-    ECC_Stop();
 }
 BENCHMARK(CCheckQueueSpeedPrevectorJob, benchmark::PriorityLevel::HIGH);

src/bench/descriptors.cpp

@@ -12,7 +12,7 @@
 
 static void ExpandDescriptor(benchmark::Bench& bench)
 {
-    ECC_Start();
+    ECC_Context ecc_context{};
 
     const auto desc_str = "sh(wsh(multi(16,03669b8afcec803a0d323e9a17f3ea8e68e8abe5a278020a929adbec52421adbd0,0260b2003c386519fc9eadf2b5cf124dd8eea4c4e68d5e154050a9346ea98ce600,0362a74e399c39ed5593852a30147f2959b56bb827dfa3e60e464b02ccf87dc5e8,0261345b53de74a4d721ef877c255429961b7e43714171ac06168d7e08c542a8b8,02da72e8b46901a65d4374fe6315538d8f368557dda3a1dcf9ea903f3afe7314c8,0318c82dd0b53fd3a932d16e0ba9e278fcc937c582d5781be626ff16e201f72286,0297ccef1ef99f9d73dec9ad37476ddb232f1238aff877af19e72ba04493361009,02e502cfd5c3f972fe9a3e2a18827820638f96b6f347e54d63deb839011fd5765d,03e687710f0e3ebe81c1037074da939d409c0025f17eb86adb9427d28f0f7ae0e9,02c04d3a5274952acdbc76987f3184b346a483d43be40874624b29e3692c1df5af,02ed06e0f418b5b43a7ec01d1d7d27290fa15f75771cb69b642a51471c29c84acd,036d46073cbb9ffee90473f3da429abc8de7f8751199da44485682a989a4bebb24,02f5d1ff7c9029a80a4e36b9a5497027ef7f3e73384a4a94fbfe7c4e9164eec8bc,02e41deffd1b7cce11cde209a781adcffdabd1b91c0ba0375857a2bfd9302419f3,02d76625f7956a7fc505ab02556c23ee72d832f1bac391bcd2d3abce5710a13d06,0399eb0a5487515802dc14544cf10b3666623762fbed2ec38a3975716e2c29c232)))";
     const std::pair<int64_t, int64_t> range = {0, 1000};
@@ -27,8 +27,6 @@ static void ExpandDescriptor(benchmark::Bench& bench)
             assert(success);
         }
     });
-
-    ECC_Stop();
 }
 
 BENCHMARK(ExpandDescriptor, benchmark::PriorityLevel::HIGH);

src/bench/ellswift.cpp

@@ -9,7 +9,7 @@
 
 static void EllSwiftCreate(benchmark::Bench& bench)
 {
-    ECC_Start();
+    ECC_Context ecc_context{};
 
     CKey key = GenerateRandomKey();
     uint256 entropy = GetRandHash();
@@ -22,8 +22,6 @@ static void EllSwiftCreate(benchmark::Bench& bench)
         /* Use the last 32 bytes of the ellswift encoded public key as next entropy. */
         std::copy(ret.begin() + 32, ret.begin() + 64, MakeWritableByteSpan(entropy).begin());
     });
-
-    ECC_Stop();
 }
 
 BENCHMARK(EllSwiftCreate, benchmark::PriorityLevel::HIGH);

src/bench/verify_script.cpp

@@ -15,7 +15,7 @@
 // modified to measure performance of other types of scripts.
 static void VerifyScriptBench(benchmark::Bench& bench)
 {
-    ECC_Start();
+    ECC_Context ecc_context{};
 
     const uint32_t flags{SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_P2SH};
     const int witnessversion = 0;
@@ -57,7 +57,6 @@ static void VerifyScriptBench(benchmark::Bench& bench)
         assert(err == SCRIPT_ERR_OK);
         assert(success);
     });
-    ECC_Stop();
 }
 
 static void VerifyNestedIfScript(benchmark::Bench& bench)

src/bitcoin-chainstate.cpp

@@ -26,6 +26,7 @@
 #include <script/sigcache.h>
 #include <util/chaintype.h>
 #include <util/fs.h>
+#include <util/signalinterrupt.h>
 #include <util/task_runner.h>
 #include <validation.h>
 #include <validationinterface.h>

src/bitcoin-tx.cpp

@@ -692,21 +692,10 @@ static void MutateTxSign(CMutableTransaction& tx, const std::string& flagStr)
     tx = mergedTx;
 }
 
-class Secp256k1Init
-{
-public:
-    Secp256k1Init() {
-        ECC_Start();
-    }
-    ~Secp256k1Init() {
-        ECC_Stop();
-    }
-};
-
 static void MutateTx(CMutableTransaction& tx, const std::string& command,
                      const std::string& commandVal)
 {
-    std::unique_ptr<Secp256k1Init> ecc;
+    std::unique_ptr<ECC_Context> ecc;
 
     if (command == "nversion")
         MutateTxVersion(tx, commandVal);
@@ -726,18 +715,18 @@ static void MutateTx(CMutableTransaction& tx, const std::string& command,
     else if (command == "outaddr")
         MutateTxAddOutAddr(tx, commandVal);
     else if (command == "outpubkey") {
-        ecc.reset(new Secp256k1Init());
+        ecc.reset(new ECC_Context());
         MutateTxAddOutPubKey(tx, commandVal);
     } else if (command == "outmultisig") {
-        ecc.reset(new Secp256k1Init());
+        ecc.reset(new ECC_Context());
         MutateTxAddOutMultiSig(tx, commandVal);
     } else if (command == "outscript")
         MutateTxAddOutScript(tx, commandVal);
     else if (command == "outdata")
         MutateTxAddOutData(tx, commandVal);
 
     else if (command == "sign") {
-        ecc.reset(new Secp256k1Init());
+        ecc.reset(new ECC_Context());
         MutateTxSign(tx, commandVal);
     }
 

src/bitcoin-wallet.cpp

@@ -128,10 +128,9 @@ MAIN_FUNCTION
         return EXIT_FAILURE;
     }
 
-    ECC_Start();
+    ECC_Context ecc_context{};
     if (!wallet::WalletTool::ExecuteWalletToolFunc(args, command->command)) {
         return EXIT_FAILURE;
     }
-    ECC_Stop();
     return EXIT_SUCCESS;
 }